A polycrystalline diamond comprising diamond particles, wherein: the content of the diamond particles is more than 99% by volume based on the total volume of the polycrystalline diamond: the median diameter d50 of the diamond particles is 10 nm or more and 200 nm or less; and the dislocation density of the diamond particles is 0.1?10.sup.15 m.sup.?2 or more and less than 2.0?10.sup.15 m.sup.?2.

A method of creating a component comprises forming a substrate and depositing a template material within the substrate, such that there are a plurality of template member. The component is heated to a temperature above a melting point of the template material, such that the template material wicks into a porosity of the substrate and forms a component with voids. An average hydraulic diameter of the voids is less than 1 millimeter.

A method for making a ceramic matrix composite component includes densifying a fibrous preform of the component with a ceramic matrix to form an intermediate component; infiltrating a hole in the intermediate component with an infiltrate material comprising a solid and a metallic alloy whose reaction forms a carbide, silicide, boride or combination thereof, heating the infiltrate material to a temperature in excess of a melting point of the metallic alloy; and sequentially cooling regions of the hole starting from an interior end of the hole to the outer surface of the intermediate component to form a solidified through-thickness reinforcement element. The hole extends in a through-thickness direction and is open to an exterior surface of the intermediate component.

Nanotube filaments comprising carbon, boron and nitrogen of the general formula B.sub.xC.sub.yN.sub.z, having high-aspect ratio and high-crystallinity produced by a pressurized vapor/condenser method and a process of production. The process comprises thermally exciting a boron-containing target in a chamber containing a carbon source and nitrogen at a pressure which is elevated above atmospheric pressure.

A method of fabricating a composite material part, the method including making a consolidated fiber preform, the fibers of the preform being carbon or ceramic fibers and being coated with an interphase; obtaining a consolidated and partially densified fiber preform, the partial densification comprising using chemical vapor infiltration to form a first matrix phase on the interphase; and continuing densification of the fiber preform by infiltrating an infiltration composition containing at least silicon and at least one other element suitable for lowering the melting temperature of the infiltration composition to a temperature less than or equal to 1150? C.

An extended length tube structure includes a first ceramic tube segment having a first end and a second end, and a second ceramic tube segment having a first end and a second end, in which the second end of the first ceramic tube segment is arranged to face the first end of the second ceramic tube segment. A ceramic coupling component is positioned to circumscribe the end-to-end configuration of the tube segments, and is sinter-bonded to the tube segments to form an continuous, extended length tube structure having a seal, such as a sinter bond or an interference bond, that is free of bond materials.

High quality, catalyst-free boron nitride nanotubes (BNNTs) that are long, flexible, have few wall molecules and few defects in the crystalline structure, can be efficiently produced by a process driven primarily by Direct Induction. Secondary Direct Induction coils, Direct Current heaters, lasers, and electric arcs can provide additional heating to tailor the processes and enhance the quality of the BN-NTs while reducing impurities. Heating the initial boron feed stock to temperatures causing it to act as an electrical conductor can be achieved by including refractory metals in the initial boron feed stock, or providing additional heat via lasers or electric arcs. Direct Induction processes may be energy efficient and sustainable for indefinite periods of time. Careful heat and gas flow profile management may be used to enhance production of high quality BNNT at significant production rates.

Methods for fabricating a ceramic matrix composite are disclosed. A fiber preform may be placed in a mold. An aqueous solution may be added to the fiber preform. The aqueous solution may include water, carbon nanotubes, and a binder. The preform may be frozen. Freezing the preform may cause the water to expand and separate fibers in the fiber preform. The carbon nanotubes may bond to the fibers. The preform may be freeze dried to remove the water. The preform may then be processed according to standard CMC process.

A printable material in ink form for forming electronic and structural components capable of high temperature performance may include a polymeric or oligomeric ceramic precursor. The material may also include a filler material and an optional liquid carrier. The ceramic precursor materials may be silicon carbide, silicon oxycarbide, silicon nitride, silicon carbonitride, silicon oxycarbonitride, gallium containing group 13 oligomeric compounds and mixtures thereof. The ceramic precursor may be deposited by a direct ink writing (DIW) process.

A method for making a composite material includes disposing a quantity of liquid comprising at least 90 weight percent molten boron within pores of a porous preform, the preform comprising a preform material; and reacting at least a portion of the molten boron with a portion of the preform material to form a solid ceramic reaction product, thereby forming a ceramic matrix composite material. An article comprises a composite material; the composite material comprises a fibrous phase disposed within a matrix. The matrix comprises silicon carbide, boron carbide, and boron silicide.